class Solution
{
    public int uniquePaths(int m, int n) {

        int[][] dp = new int[m + 1][n + 1];
        dp[0][1] = 1;
        for(int i = 1; i <= m; i++) // 从上往下每⼀⾏
            for(int j = 1; j <= n; j++) // 从左往右填写每⼀⾏
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
        return dp[m][n];
    }
}